/*
 *  Licensed to the Apache Software Foundation (ASF) under one
 *  or more contributor license agreements.  See the NOTICE file
 *  distributed with this work for additional information
 *  regarding copyright ownership.  The ASF licenses this file
 *  to you under the Apache License, Version 2.0 (the
 *  "License"); you may not use this file except in compliance
 *  with the License.  You may obtain a copy of the License at
 *
 *    https://www.apache.org/licenses/LICENSE-2.0
 *
 *  Unless required by applicable law or agreed to in writing,
 *  software distributed under the License is distributed on an
 *  "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY
 *  KIND, either express or implied.  See the License for the
 *  specific language governing permissions and limitations
 *  under the License.
 */
package org.grails.core.support.internal.tools;

import groovy.lang.MetaClass;
import groovy.lang.MetaClassRegistryChangeEvent;
import groovy.lang.MetaClassRegistryChangeEventListener;

/**
 * Simple class that reports when meta class changes and where (in what stack frame) those changes took place
 *
 * @author Graeme Rocher
 * @since 2.0
 */
public class MetaClassChangeReporter implements MetaClassRegistryChangeEventListener {
    /**
     * Called when the a constant MetaClass is updated. If the new MetaClass is null, then the MetaClass
     * is removed. Be careful, while this method is executed other updates may happen. If you want this
     * method thread safe, you have to take care of that by yourself.
     *
     * @param cmcu - the change event
     */
    public void updateConstantMetaClass(MetaClassRegistryChangeEvent cmcu) {
        Class<?> classToUpdate = cmcu.getClassToUpdate();
        MetaClass newMetaClass = cmcu.getNewMetaClass();

        System.out.println("Class [" + classToUpdate + "] updated MetaClass to [" + newMetaClass + "]");
        Thread.dumpStack();
    }
}
